Semicoherent interface formation and structure in InAs/GaAs(111)A heteroepitaxy

A theoretical analysis based on atomistic simulations is presented of both the semicoherent interface structure, which is formed to relax the strain d ue to lattice mismatch during InAs/GaAs(111)A heteroepitaxy, and the energe tics of interface formation. The semicoherent interface consists of a netwo rk of intersecting misfit dislocations, which includes both perfect 90 degr ees dislocations along [112] directions and Shockley partials along [110]di rections that bound faulted interfacial regions. This interface structure b ecomes stable for film thicknesses greater than four monolayers. Our simula tion predictions of the interface structure and the critical film thickness for full strain relief are in excellent agreement with recent experimental data. (C) 1998 Elsevier Science B.V. All rights reserved.